Many retaining walls—walls constructed to prevent soil, rock and/or other materials from moving to an undesired location—now include a geogrid coupled to the wall that extends into the soil, rock and/or other materials to help retain the materials. Frequently, such retaining walls are constructed from blocks that are placed on top of each other. With the use of such blocks, one has a great degree of flexibility in the final design of the wall, such as the height of the wall, the length of the wall, and the curvature of the wall. The geogrid frequently coupled to such walls is typically a screen mesh made of plastic rods that intersect each other (typically at 90°) and are spaced apart as desired to provide the desired support for the average particulate size of the material retained by the wall.
To couple the geogrid to the wall, a portion of the geogrid is typically placed between two or more blocks of the wall and held between the blocks by friction between the geogrid and the blocks. For example, FIG. 1 shows a perspective, partial cut-away view of a conventional retaining wall 20 that has a geogrid 22 coupled to it. The wall 20 includes a plurality of blocks 24 stacked on top of each other. To couple the geogrid 22 to the wall 20, a portion of the geogrid 26 is inserted between some of the blocks 24. The geogrid 22 is held in place by the friction between the geogrid portion 26 and the blocks 24 above the portion 26 and the blocks 24 below the portion 26
Unfortunately, coupling the geogrid 22 to the wall 20 in this manner often doesn't secure the geogrid 20 to the wall 20 well enough. If a moderate amount of pressure is exerted on the geogrid in the direction shown by the arrow 28, or exerted on the wall 20 in the direction shown by the arrow 30, the portion 26 of the geogrid 22 may move relative to the blocks 24 immediately above and below the portion 26. This may be especially true when the wall 20 is short in height, because with such a wall the friction between the portion 26 and the blocks 24 is significantly reduced relative to a taller wall. The friction is significantly reduced because the amount of weight provided by the blocks 24 above the portion 26 of the geogrid 22 is much less for a short wall relative to a tall wall.